Every thing works bt no display on display window.

Hi, The black screen problem means the lens sensor is spoiled due to over exposure to heat. Its better to give it to cannon service centre. If your camera is under warranty period its well and good they will replcae the lense sensor for free of cost.

If every part is working properly why do we have no picture? Flash would have no bearing unless you're are testing in a darkened room. What makes you think it's not the shutter? If your car suddenly stopped running and the mechanic told you the big end was gone would you say "it can't be, the radio is working"

If the shutter was at fault it would certainly result in a black screen. It could well be the CCD or even the LCD. Unfortunately these are items beyond most people's ability to test so a qualified tech with the associated test equipment would be needed. The best bet being the authorised agent. Do I detect a possibility that perhaps you've had the back off the camera for a look? If you have you could have caused any amount of damage simply by doing so.

I remember about 25 years ago a lady came into my repair shop and told me her TV wanted a new on/off switch. I asked what made her think it was faulty, she replied "because it won't switch on you silly man" True story.